Allison is growing a few beds of sunflowers and giving each group different amounts of water for a period of five weeks to see if it affects their growth. All of the groups receive the same amount and type of soil, and receive the same amount of sunlight. She gives the first sunflower group 300 extra milliliters of water a day. The second receives 200 extra millilitres of water a day and the third bed of sunflowers receives no extra water and obtains water only natural ways. Allison records the heights of the sunflowers after each week. what is the: •IV: •DV: •Constants: •Control: